For certain situations, end-users need the base path for Elasticsearch
logs. Exposing this as a property is better than hard-coding the path
into the logging configuration file as otherwise the logging
configuration file could easily diverge from the Elasticsearch
configuration file. Additionally, Elasticsearch will only have
permissions to write to the log directory configured in the
Elasticsearch configuration file. This commit adds a property that
exposes this base path.
One use-case for this is configuring a rollover strategy to retain logs
for a certain period of time. As such, we add an example of this to the
documentation.
Additionally, we expose the property es.logs.cluster_name as this is
used as the name of the log files in the default configuration.
Finally, we expose es.logs.node_name in cases where node.name is
explicitly set in case users want to include the node name as part of
the name of the log files.
Relates #22625
fc3280b3cf